Chesapeake Energy Corporation is the second-largest producer of natural gas, the 11th largest producer of oil and natural gas liquids and the most active driller of onshore wells in the U.S. Headquartered in Oklahoma City, the company's operations are focused on discovering and developing unconventional natural gas and oil fields onshore in the U.S. Chesapeake owns leading positions in the Eagle Ford, Utica, Granite Wash, Cleveland, Tonkawa, Mississippi Lime and Niobrara unconventional liquids plays and in the Marcellus, Haynesville/Bossier and Barnett unconventional natural gas shale plays. The company also owns substantial marketing and oilfield services businesses through its subsidiaries Chesapeake Energy Marketing, Inc. and Chesapeake Oilfield Services, L.L.C.